Porphyromonas gingivalis Outer Membrane Vesicles Promote Apoptosis via msRNA-Regulated DNA Methylation in Periodontitis.

The outer membrane vesicles (OMVs) produced by Porphyromonas gingivalis contain a variety of bioactive molecules that may be involved in the progression of periodontitis. However, the participation of P. gingivalis OMVs in the development of periodontitis has not been elucidated. Here, we isolated P. gingivalis OMVs and confirmed their participation in periodontitis both in vivo and in vitro. Microcomputed tomography (micro-CT) and histological analysis showed that under stimulation with P. gingivalis OMVs, the alveolar bone of rats was significantly resorbed in vivo. We found that P. gingivalis OMVs were taken up by human periodontal ligament cells ([hPDLCs]) in vitro, which subsequently resulted in apoptosis and inflammatory cytokine release, which was accomplished by the microRNA-size small RNA (msRNA) sRNA45033 in the P. gingivalis OMVs. Through bioinformatics analysis and screening of target genes, chromobox 5 (CBX5) was identified as the downstream target of screened-out sRNA45033. Using a dual-luciferase reporter assay, overexpression, and knockdown methods, sRNA45033 was confirmed to target CBX5 to regulate hPDLC apoptosis. In addition, CUT&Tag (cleavage under targets and tagmentation) analysis confirmed the mechanism that CBX5 regulates apoptosis through the methylation of p53 DNA. Collectively, these findings indicate that the role of P. gingivalis OMVs is immunologically relevant and related to bacterial virulence during the development of periodontitis. IMPORTANCE P. gingivalis is a bacterium often associated with periodontitis. This study demonstrates that (i) sRNA45033 in P. gingivalis OMVs targets CBX5, (ii) CBX5 regulates the methylation of p53 DNA and its expression, which is associated with apoptosis, and (iii) a novel mechanism of interaction between hosts and pathogens is mediated by OMVs in the occurrence of periodontitis.

Extracellular Vesicles: An Emerging Regenerative Treatment for Oral Disease.

Extracellular Vesicles (EVs) are small lipid-enclosed particles containing biological molecules such as RNA and proteins that have emerged as vital modulators of intercellular communication. Increasingly, studies have shown that EVs play an essential role in the occurrence and prognosis of oral diseases. EVs are increasingly considered a research hotspot of oral diseases. In addition, the characteristics of carrying active molecules have also been studied in oral tissue regeneration. Evidence has shown that EVs regulate the homeostasis of the inflammatory microenvironment, promote angiogenesis, and repair damaged tissues. In this review, we summarized the characteristics of EVs and highlighted the role of EVs in oral tissue regeneration, including dental pulp, periodontal tissue, cartilage, and bone. We also discussed their deficiencies and prospects as a potential therapeutic role in the regeneration treatment of oral disease.

Functional Polymorphisms of CTLA4 Associated with Aggressive Periodontitis in the Chinese Han Population.

BACKGROUND/AIMS: CTLA4 has been identified functioning as a protein receptor which functions as an immune checkpoint, downregulating the immune system. Susceptibility to aggressive periodontitis (AgP) is influenced by gene polymorphisms related to the immune response. In this study, we focused on SNPs in the 3'-UTR of CTLA4 among Chinese AgP patients, and investigated any further relationships between the SNPs and miRNAs. METHODS: This case-control study included 120 AgP patients and 150 healthy controls. Genotyping was used to detect allele distribution. Cell transfection and the dual luciferase reporter assay were performed to investigate the potential functions of SNPs located in the 3'UTR of CTLA4. RESULTS: The data show that patients with a history of smoking were more susceptible compared to controls, exhibiting deeper probing depth, greater attachment loss and more sites of bleeding on probing. The results of genotyping analysis revealed that individuals with the GA and AA genotypes, and with the A carrier had a decreased risk (P = 0.015, P = 0.03). Furthermore, patients with the G allele might be regulated by miR-105, which caused a down-regulation of CTLA4. The carriers of the GG genotype exhibited the worst results of attachment loss and bleeding on probing. CONCLUSION: These findings show that rs56102377 in the 3'-UTR of CTLA4 may act as a protective factor by disrupting the regulatory role of miR-105 in CTLA4 expression. Thus, our study highlighted a potential role of these polymorphisms as genetic susceptibility biomarkers of periodontitis in Chinese Han populations.

Interleukin-10 polymorphisms affect the key periodontal pathogens in Chinese periodontitis patients.

Interleukin-10 (IL-10) polymorphisms have been shown to affect IL-10 production. This study investigated the influences of IL-10 polymorphisms on the susceptibility to chronic periodontitis (CP) and aggressive periodontitis (AP), and their possible role in the quantity of subgingival bacteria Aggregatibacter Actinomycetemcomitans and Porphyromonas gingivalis. 92 CP patients, 83 AP patients and 91 periodontal healthy controls were recruited. Serum IL-10 concentration was analyzed by enzyme-linked immunosorbent assay (ELISA). Gene polymorphisms were determined by multiplex SNaPshot technique. Bacteria were quantified by real-time polymerase chain reaction with TaqMan MGB probes. Taking into account age, gender and periodontal status, IL-10-592 AA, -819 TT and ATA/ATA genotype occurred more frequently in patients with CP than in healthy controls. In CP cases, higher quantity of subgingival A. actinomycetemcomitans and lower serum IL-10 levels could be detected in homozygous ATA/ATA carriers. These findings indicate that variants in IL-10 promoter gene were not only associated with predisposition to chronic periodontitis but also affected the subgingival number of A. Actinomycetemcomitans in a Chinese Han population.